Comparison of the Minimum Plateau Width by Plateau and a New Method in People with Conductive Hearing Loss

BACKGROUND AND OBJECTIVES: In clinical masking, the plateau is a state in which the non-test ear (NTE) is completely masked by the noise and tone is heard only by the test ear (TE). At least 15 to 20 dB of plateau width is needed to obtain valid threshold. In the study, a part of plateau after initial masking level known as the minimum plateau width (mPW) was determined and compared by a new formula and the plateau searching method. SUBJECTS AND METHODS: Minimum plateau widths of air conduction were obtained in 29 participants with unilateral and 30 participants with bilateral conductive hearing loss (CHL) aged 20 to 45 years old by using step by step plateau method and mPW estimation by the formula between two points of masking diagram [mPW=(N2-N1)-(T2-T1)] and then the mPW of two methods was compared for each frequency. RESULTS: There was no significant difference between the minimum plateau width obtained by the plateau and formula methods for two given point of masking diagram in people with unilateral and bilateral CHL at octave frequencies from 500 Hz to 4,000 Hz. CONCLUSIONS: Threshold obtaining of TE by two tones for two noise levels delivered to the NTE is enough to estimate the mPW between these two noise points and it is not necessary that for clinicians to know the actual values of masking diagram components.

Middle Turbinate Osteoma

Osteoma is the most common benign tumor of the paranasal sinuses. Turbinate osteomas are very rare and only four middle turbinate, one superior turbinate and one inferior turbinate osteoma cases have been reported. We present a rare case of osteoma of the left middle turbinate in a patient presented with unilateral nasal obstruction and epiphora that was removed endoscopically, and conduct a literature review on turbinate osteomas arising from different turbinates, their symptoms and management.

[Comparison of the prevalence and latency of vestibular evoked myogenic potentials in normal participants and symptomatic and asymptomatic Meniere's disease patients]

Vestibular evoked myogenic potentials [VEMP] originate from the saccule and the inferior vestibular nerve. In this study, the prevalence of VEMP and latency of the p13 and n 23 were compared between three groups of individuals, including symptomatic and asymptomatic Meniere's disease cases and normal participants. This study was conducted on 42 cases with the mean age of 40.48 years; thirty were Meniere's disease patients, of which 19 were symptomatic and 11 were asymptomatic; twelve were normal participants. The VEMP were recorded with 500 Hz tone bursts at 120 dBpeSPL. Then the prevalence and latency of the waves were analyzed and compared in the three above mentioned groups. The prevalence of VEMP in symptomatic Meniere's disease patients [52.6%] was significantly less than asymptomatic individuals [90.9%] and also normal subjects [100%] [p<0.05]. There was no significant difference between latencies of the waves in these three groups [p>0.05]. The latency of p13 for symptomatic, asymptomatic and normal participants was 16.41, 15.20 and 14.14 ms, respectively and the latency of n23 for these groups was 20.25, 18.77 and 18.50 ms, respectively. In Meniere's disease, after medical management, the succule probably regains normal function resulting in re-existence of VEMP. It seems that there is no change in the latency of the waves, most likely in re-existence of VEMP. It seems that there is no change in the latency of the waves, most likely due to involvement of the inner ear and intactness of the nerve. VEMP may be a useful test for diagnosis of Meniere's disease and additionally for monitoring the trend of medical management

Relative frequency of GJB2 gene mutations in autosomal recessive non-syndromic hearing loss [ARNSHL] patients in lurastan population

Congenital hearing loss with many genetic and environmental causes affecting 1 in 1000 newborns. Mutations in the GJB2 [Gap Junction Beta-2] gene encoding the gap junction protein connexin 26 have been established as the main cause of autosomal recessive non-syndromic hearing loss. The aim of this study was to study the frequency of GJB2 mutations in Lurastan non-syndromic deaf population using ARMS/PCR, DHPLC and direct sequencing. For this purpose, 106 chromosomes from 53 patients were studied. Eighteen chromosomes [17%] carry GJB2 mutations including 35delG, 314dell4, 512insAACG, -3170G>A, W24X, V95M and 510insCGAA. The last mutation is a novel GJB2 mutation, 35delG mutation was diagnosed in 10 chromosomes [9/4%]; 4 patients were homozygote and 2 patients were heterozygote. Also polymorphism VI531 were found in 3 families. This frequency is significantly higher compared to that of the whole population of Iran